1. Technical Field
This invention relates to passenger conveyors in general, and to balustrade skirt panels for passenger conveyors in particular.
2. Background Art
Escalators, moving walkways, and other passenger conveying devices efficiently move a large volume of pedestrian traffic from one point to another. Passengers step on moving treadplates (e.g. steps, belts, pallets, etc.) and are transported along at a constant rate of speed. For safety reasons, passenger handrails are provided, traveling in the same direction and speed as the treadplates. A balustrade assembly supports and guides one of the handrails on each side of the treadplates.
Each balustrade assembly includes a balustrade panel which extends up from a base to support the handrail. Externally, the base consists of an outer decking, an inner profile, and a skirt panel. The outer decking encloses the mechanics on the side of the balustrade panel opposite the moving treadplates. The inner profile encloses the mechanics adjacent the moving treadplates. The inner profile also provides a transition section between the balustrade panel and the skirt panel.
The skirt panel lies in close proximity to, but out of contact with, the moving treadplates. Because of the proximity to the moving treadplates, the skirt panel must be a rigid panel to prevent pinching between the panel and the treadplates. Skirt panels typically are assembled from structural members and sheet metal. The sheet metal provides the surface in close proximity to the treadplates and the structural members add rigidity to the fabrication. It is known in the art that the hardware necessary to locate and hold the skirt panel relative to the treadplates may be incorporated into the structural members. For example, if bolts with "T"-shaped heads are employed to locate and position the skirt panel, mating "C"-shaped channels are used as the structural members.
There are several disadvantages to assembled skirt panels. First, the structural members and the sheet metal faces must be attached by weld or by fasteners. Either way, the exposed panel face is marred by heat discoloration or by fasteners. Second, to achieve an assembled skirt panel of sufficient stiffness, it is necessary to use sheet metal and structural members of considerable strength. As a result, the assembled skirt panel is more expensive, cumbersome to work with, and requires more space and stronger mounting hardware. Third, creating an assembly adds manufacturing steps, and therefore time and expense to the manufacturing process. Fourth, the assembled elements of the skirt panel may vibrate free and create undesirable noise. A person of ordinary skill in the art will recognize that the "quietness" of a passenger conveyor is perceived as an indication of the quality of the device. In sum, fabricated skirt panels have several considerable disadvantages.